Up to now, there is a lighting device disclosed in Patent Literature 1. In the lighting device, a light source (for example, LED) and a drive circuit (for example, an LED drive unit, a control unit) that drives the light source to emit a light are fitted to a heat sink. The heat sink radiates a heat generated by the light source during lighting, and also radiates a heat generated in the drive circuit.
As described above, the lighting device can radiate not only the heat generated by the light source during lighting, but also the heat generated in the driver circuit by the heat sink. However, in the lighting device, the light source and the drive circuit are fitted to the same heat sink. For that reason, in the lighting device, the heat generated by the light source during lighting is transmitted to circuit elements configuring the drive circuit through the heat sink. Hence, the lighting device has the potential to decrease the heat radiation of the circuit elements.